What is 1/2 - 2/9?

Here's how to subtract 2/9 from 1/2:

1

2

−

2

9

Step 1

We can't subtract two fractions with different denominators. So you need to get a common denominator. To do this, you'll multiply the denominators times each other... but the numerators have to change, too. They get multiplied by the other term's denominator.

So we multiply 1 by 9, and get 9.

Then we multiply 2 by 2, and get 4.

Next we give both terms new denominators -- 2 × 9 = 18.

So now our fractions look like this:

9

18

−

4

18

Step 2

Since our denominators match, we can subtract the numerators.

9 − 4 = 5

So the answer is:

5

18

Step 3

Last of all, we need to simplify the fraction, if possible. Can it be reduced to a simpler fraction?